1. Field of the Invention
The invention relates to the field of small-motion test apparatus.
2. Prior Art
Devices which test the ability of a subject to control limited motion have been developed in the art, both as games and for psychological testing purposes, although most such test devices have been one-dimensional. For example, Campbell U.S. Pat. No. 3,232,610 shows a magnetic target game wherein a wand must be inserted into a small aperture between magnets toward a target. Two patents to Olalainty U.S. Pat. Nos. 2,958,956, and 3,029,526 disclose psychological test apparatus wherein the user is to follow a sinuous track with a wand. Means are also provided for checking pressure of fingers on the stylus and the pressure of the stylus on the track, although only against a single upper threshold. The pressure of fingers and of the wand are checked using capacitive relays which are energized if the capacity exceeds a predetermined level. The slant of the stylus may be checked by energizing the sides of the track to detect contact with the wand.
A patent to Kavakos U.S. Pat. No. 3,208,747 shows a game wherein a stylus carrying a conductive loop is moved down a charged wire, the object being to move the loop down the wire without touching the wire. A patent to Braund U.S. Pat. No. 2,521,500 shows a system wherein a wand must be guided along a track from one end to the other within a fixed time. None of these devices utilizes an electrified target movable only within a defined envelope of freedom of movement under control of a stylus or wand as an integral part of the test apparatus. Nor do any of these earlier devices incorporate the rate at which the electrified target or wand moves as an integral part and continuing part of the test procedure; nor do any of them set upper and lower limits on the allowable vertical movement of the target. Thus as far as continuously-monitored variables are concerned, the prior art test environments are essentially one-dimensional.
The inventor is also aware of devices which move a target at a controlled rate to be followed by a wand. But as far as is known, the target itself does not carry the sensing mechanism, nor is there any control of the vertical movement of the target by the test subject, which results in a significant loss of test variables in such a prior art device. With such a device the test subject can merely follow the target with the wand he holds, rather than provide affirmative control of its orientation. Such a device is disclosed in Schow U.S. Pat. No. 3,867,769 wherein the target only carries a photocell 140 for sensing target tracking; the other test variables are monitored using switches carried on the test wand itself (FIGS. 2, 3, 4). The result is an unwieldly, unrealistic test wand of complex mechanical structure, without any simplification of the target track structure (see FIGS. 5, 6 of Schow).
Prior art small-motion devices are known which attempt to test another variable than linear motion, e.g., those patented by Olalainty, test the vertical orientation of the target achieved by the test subject by using complicated electronic means such as variable capacitance devices. Such devices are difficult to calibrate accurately and to re-use with consistent accuracy.